Means for reducing bulging of crusher jaw face-plates



Sept. 2, 1952 R. v. BAKER 2,609,154

MEANS FOR REDUCING BULGING OF CRUSHER 'JAW FACE-PLATES Filed April 7, 1949 H EA V. BAK

Snventoi' Gttornegs;

Patented Sept. 2, 1 952 MEANS FOR REDUCING BllLGING or CRUSHER JAW FACE-PLATES Rhea V. Baker, Seattle, Wash. Application April 7-, 1949, Serial No. 85,982

This invention relates to a means for reducing bulging of crusher jaw face-plates and, more particularly, is the provision in manganesesteel crusher face plates of a construction that is less bulging under the peening action during material-crushing operations.

In crushingrock and ore and other hard substances by the use of jaw crushers, of the type having a fixed and a vmovable jaw that are caused to open and close as material passes between them, considerable difliculty arises because of undue deterioration of the jaws. A commonly observed symptom of trouble with the jawsis evidenced during crushing when the machine begins to belch material out thetop or inlet opening. If, during crushing, a careful record is kept of the operation of the machine. the operator will notice a decreasingefiiciency as the output falls, but at the same time, no particularly observable change in the mechanical operation of the crusher. The problem has been aggravated since the adoption and use of manganese-steel alloys in forming the faceplates more than before whenthe plates wereformed of cast iron. A factor in the problem appears to lie in. the use today of thinplates permitted by the great wear resistance of the a manganese-steel alloy material. Formerly when the plates were quite massive and of substantially greater thickness, belching was not such a noticeable condition. The thinner plates have been made possible because. of the improved characteristics imparted through the use of manganese. Manganese has a ductility thatallows it to flow under an impact that would not produce a similar reaction in castiron or cast steel. It is this ductility that I have found to be a major cause.of.belching in the jaw crushers.- What occurs appears to be this: as.

the jaws open and close on hard materials, the face-plates are subjectedto a multitude of. facial impacts that cause a peening of the facing metalof the face-plates. The face of the plate grows in its longitudinal and lateral axesand, since therear face of the plate does not similarly grow, the plateiswarped or bulged in the axes mentioned. This causes the plate to draw away in the middle of port to which it is attached and to acquirea concavo-convex shape and springy characteristic of such a nature that when a.rock, for example, is disposed between two such plates and resists crushing, even though the jaws are closing, it

deflects the bulged jaws toward, their base until finally a slippage occurs and the rock is forced upward toward the inlet opening of the jaw the back from the sup-,

' a clai s. (01. 241 2e1') crusher. The action is much like that when a person squeezes a marble between his thumb and forefinger without equal pressure on both sides to cause the marble to fly out between the ends of his thumb and finger. In the jaw crusher this is what appears to occur when the machine is belching. Quite naturally when rock is slipping or flying backward from a crusher the machine is losing or has lost efficiency and its output will fall off.

I have further observed during my extended experience with jaw crushers, that bulged jaws will produce very undesirable wear on the base to which a fixed face-plate is' secured and on the pitman arm to which the movable face-plate is attached. When the plates bulge in either or both axes, the bearing of the plate on its support is reduced to lines of contact or points of contact. Such a bulged 'jaw is fi ex'ed 'and unfiexed during crushing and excessive pressures are applied on small areas to 'suchan extent that wear of the support occurs and depressions rapidly form in the support elements. Should. the bulged jaws be replaced: by: new flat jaws, the latter will not then be supported atthe corners or edges and a rocking a'ction' into and out of the depressions occurs that is undesirable. To overcome this difiicu1ty,a welder.

will have to tediously fill the depressions-with to resume their original flat condition. -'IThe;

grooves remained open. When these jaws were again mounted in a crusher and used, it soonbecame apparent that they had a longer useful life than originally, because they did not bulge even though. used harder and longer-than be tween the first installation andftheir first re-.-

moval' in the bulgedcondition. Itwas n0tedv that while the metal of the face of thelr'idges still appeared to move or flowv under the many.

impacts during crushing, it flowed intothe open grooves that had I been cut across the. ridges where slightly overhanging and quite friable lips were formed. These lips would tend tojgrow? away from the brink of the groove until they ing face wider or longer than the back face. I

Further experimentation teaches that it is desirable to form a network of grooves the widths of which are less than the space between grooves which constitute the crushing pads of the faceplate. With such a construction it is possible to produce a long-wearing, non-bulging, faceplate of manganese-steel alloy that will largely eliminate belching of a crusher and will prolong the high output period of the jaw faceplates over what has heretofore been possible.

My invention is more fully described in the following specification, during a. reading of which other objects and advantages of the invention will become apparent, and disclosed in the accompanying drawings, in which:

Figure l is a vertical sectional view of a jaw crusher, having face-plates therein according to my invention;

. Figure 2 is a perspective view of a face-plate for a jaw crusher showing a preferred form of face configuration; v

Figure 3 is a longitudinal sectional view through the plate of Figure 2 as taken on line 3-3 thereof;

Figure 4 is a diagonal sectional view on line 4-4 of Figure2; and

Figure 5 is an enlarged detail view in section showing how a facial increment of a growing face-plate is broken away from an edge of a groove during normal operation of a jaw crusher equipped according to my invention.

Essentially my method of reducing bulging in manganese-steel face-plates comprises forming in the face of the plate, a network of grooves which divides the crushing face into a plurality of isolated, island-like, crushing pads. The metal on the face of the pads can then move as under the peening action of rock laterally of the plate and into the grooves at their outer edges. This swaged metal increment of the plate face tends to overhang the grooves, and, as it grows outward into the groove, become more friable or weakened until rock will break off particles and tend to clear the grooves. By arranging the grooves in the plate so that they extend obliquely of the direction of material past the face-plates, the crushing pads have a diamond shape and certain of the corners of the pads are positioned to resist movement of the crushable material laterally or longitudinally of the face-plate.

Referring particularly to Figure 1 of the drawings, I show a crusher frame l0, having opposed base elements 12 and I4 on opposite sides of the machine. The base 14 backs up the pull wedge I6 against which rests the bearing wedge l8. Pull wedge I6 is adjusted vertically by the adjusting bolts 20. The frame In journals the eccentric shaft 22 which has flywheel 24 on one end and is driven by conventional means on the other end. Pitman 26 is actuated by the eccentric shaft 22 and is held in spaced relation to the bearing wedge I8 by means of the toggle plate l9 and the tensioning means 28. Pitman 26 carries the movable face-plate 30 and frame base member l2 carries the fixed face-plate 32. Normally the face-plates are thin and formed of manganesesteel alloy which is very wear-resisting under hard use due to the ductility imparted by the manganese component. Rotation of the eccentric shaft 22 causes the movable jaw .to move toward and away from the fixed jaw in a crushing action on material placed there from above.

In Figure 1 the dotted lines 34 indicate the nature in which the heretofore used jaws bulge away from their supports, a condition which my invention overcomes.

The face-plate 32 of Figure 2 is of the type used on the fixed base I2 but is, so far as the facial arrangement is concerned, typical of the plate 30 that is mounted on the pitman arm 26. In this instance I have formed grooves 40 and 42 which are disposed obliquely of the rectangular face-plate and intersect to form a network of grooves over the face of the plate. With this arrangement a plurality of diamond-shaped crushing pads 44 are formed on the plate face with their corners directed in line with the lateral and longitudinal axes of the plate. On the receiving and discharging edges of the plate, 46 and 48 respectively, I terminate the oblique grooves short of the plate edge and provide auxiliary grooves 50, which separate the plate across its width into pentagonal pads 52.

The diamond shape of the pads 44 and their arrangement with certain of the corners in line with the longitudinal axis of the plate accomplishes a gripping effect on rock as it is being crushed. The corners of the pads are, in effect, teeth that are spaced apart by the interstices of the grooves and which grip or bite into the rock to hold it against slipping out from between the jaw plates.

As rock is crushed between these plates, the metal on the face of the pads tends to move laterally of the crushing face in the manner suggested in Figure 5 and to form overhanging lips 54 that are of metal that has been peened by the rock and the many blows delivered by the latter to the crusher face. These lips 54, as they are extended more and more from the solid pad, become brittle or friable to such an extent that eventually a rock R will break them off. This means that the lips cannot grow enough across the mouth of the groove so that they can come together and cause a substantial extensional pressure to be applied to warp or bulge the face-plate.

Throughout this specification I have referred to the use of my invention in connection with manganese-steel crusher jaws, but I wish to point out that the cast steel jaws are, to a certain extent, similarly accompanied with the problem of bulging or bowing out and that the invention is equally applicable thereto.

The preferred form of my network of grooves has been shown in connection with the provision of oblique or diagonal grooves on the face of the crusher jaw. It is to be understood that the network is not necessarily limited to the formation of diamond-shaped crushing pads as the geometric configuration on the face of the jaw to obtain substantially the same results can be widely varied. For example, a plurality of annular peripherally intercommunicating grooves could be employed in which case there would be circular pads and intervening concave-edged diamonds. Or the grooves, while diagonal, could be sinuous, in which case the pads would not be straight-edged diamonds but would approximate that shape. Other geometric shapes will occur to the mechanic skilled in the art without difficulty and these are deemed to be part of my invention.

Having thus described my invention, I claim:

1. A face-plate for jaw crushers for crushing rocks and ore, comprising: a rigid, rectangular, plate-like body of manganese-steel having a fiat forward crushing face to be mounted upright in a crushing mechanism with its back against a fiat supporting surface on which it bears during crushing, said body having formed in the crushing face a first and a second series of parallel grooves having substantially parallel walls and extending obliquely of the direction of travel of crushable material past said face, the grooves being small in comparison to the areas between the grooves and said areas between the grooves lying substantially in a common plane, the grooves of the first series intersecting with the grooves of the second series at abrupt angles and dividing said crushing face into a network of grooves and diamond-shaped crushing pads isolated from each other by said grooves, whichpads serve to prevent lateral shift of material being crushed and tend to urge crushable material downward in such crushing mechanism while resisting the tendency of the same to belch, and said grooves permitting the movement of surface metal of said pads under crushing blows to avoid the accumulation of bulging stresses in said face-plate, said grooves having substantial width in relation to the size of rock and ore to be crushed whereby when surface metal moves laterally of the face-plate and forms overhanging lips at the edge of said grooves, the lips are broken before they bridge the grooves.

2. The structure according to claim 1 in which said grooves extend into said face-plate at least half its thickness.

3. A manganese-steel face-plate for jaw crushers for crushing rocks, ore and like large hard materials, comprising: a rigid, rectangular, platelike body having a flat forward crushing face to be mounted upright in a crushing mechanism with its back against a flat supporting surface on which it bears during crushing, said body having formed in the crushing face a first and second plurality of parallel grooves of considerable depth being small in comparison to the areas between the grooves and said areas between the grooves lying substantially in a common plane, the grooves of said first plurality intersecting the grooves of said second plurality at abrupt angles I and dividing said crushing face into a network of grooves and diamond-shaped crushing pads isolated from each other, certain of said grooves of said pluralities terminating short of the receiving and discharging edges of said plate and being connected with said edges by a third plurality of grooves extending in line with the direction of travel of crushable material to form polygonal crushing pads at the receiving and discharging edges of said face-plate, which said diamond shaped crushing pads serve to prevent lateral shift of material being crushed and tend to urge crushable material downward in said crusher while resisting the tendency for the same to belch, and said grooves permitting the movement of surface metal of said pads under crushing blows to avoid the accumulation of bulging stresses in said face-plate, said grooves having substantial width in relation to the size of rock and ore to be crushed whereby when surface metal moves laterally of the face-plate and forms overhanging lips at the edge of said grooves, the lips are broken before they bridge the grooves.

RHEA V. BAKER.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 489,723 Titus Jan. 10, 1893 528,405 Welch Oct. 30, 1894 874,764 Halstead Dec. 24, 1907 883,619 Canda Mar. 31, 1908 993,783 Mason May 30, 1911 1,443,213 Chaney Jan. 23, 1923 1,593,153 Ambler July 20, 1926 2,449,746 Kinkel Sept. 21, 1948 

